Treating textile materials



dill tit Patented Apr. 3, 1934 TREATING TEXTILE MATERIALS Carl Z. Draves, Longmeadow, Mass., and Herbert A. Lubs and Herbert W. Walker, Wilmington, Del., assignors to E. I. du Pont de Nemours & Company, Wilmington, Del., a corporation of Delaware No Drawing. Application March 25, 1932, Serial No. 601,288-

, 18 Claims. (01. 8-5) This invention relates to the treatment of materials dyed with sulfur dyes to prevent or retard tendering therein, and to the products resulting from such treatment. It especially contemplates the prevention of tendering in sulfur black dyed materials.

As is well known, sulfur dyes, and especially sulfur black dyes, are extensively used for the production of fast shades at low cost on various kinds and grades of textile materials (fabrics, yarns, thread and raw stock). The advantages of these dyes are considerably overshadowed and the use thereof somewhat limited by the fact that under certain conditions of storage, for example, such as in a warm, humid atmosphere; there is a tendency for materials colored with these dyes, particularly those dyed with sulfur blacks, to tender, that is, to undergo deterioration resulting in the reduction of tensile strength.

It is an object of the present invention to pro duce materials dyed with sulfur dyes, particularly sulfur black dyes, which are highly resistant to tendering. A further object oi. the invention is the provision of a new and improved process for producing materials of the character above described. Dther objects of the invention will be apparent'by reference to the following description thereof.

These objects are accomplished according to this invention whereby dyed fibers and fabrics highly resistant to tendering are produced by treating materials dyed with sulfur dyes, more particularly sulfur black: dyes, to incorporate therewith a soap and a soluble salt of hydro fiuoric acid. This may be effected by passing the materials through a solution containing a soap and a soluble fluoride. The resultant product may thereafter be dried in a suitable manner so that the soap and soluble fluoride remain thereon. When convenient or necessary the dyed material may be saturated with the solution or suspension and squeezed, wrung out or hydroextracted bei'cre drying.

Since it is customary to subject dyed materials to treatment with finishing mixtures containing such substances as starch, dextrine, tallow, etc., in practicing the present invention it may be convenient and desirable to introduce the soap and soluble fluorides into the finishing mixture. This modification oi the invention should not be used when the finishing mixture includes salts of calcium, magnesium or zinc as is often the case. With this modification of the process, the materials are given a finish and are protected against tending at the same time.

While the invention is susceptible of considerable variation and modification in the manner of its practical application, particularly as regards the proportions of materials employed and the exact method of procedure used in applying the 6 soap and fluoride to the fibre or fabric treated, the following examples, in which the proportions are given in parts by weight, will serve to illustrate how the invention may be practiced.

Example I Cotton raw stock was dyed with 10% (based on the weight of the fibre) of sulfogene carbon HXX, a sulfur black dye prepared by thionating dinitrophenol, and the dyed material was spun into yarn and woven into a fabric. The cloth from the loom was finished in the usual manner (passed through warm water, dried, and sized. with starch) except that the finishing mixture applied to the dry fabric in the starch mangle iii contained 3 parts of sodium fluoride, 2 parts of granulated soap and part of tri-sodium. phosphate in 100 parts of finishing mixture. In the starch mangle the cloth took up solution to the extent of about of its own weight. 8d

Samples of this treated cloth, and samples of similar cloth finished without any soap and fiuor I ide were tendered by heating for '70 hours at 127 C. in an oven. After this-accelerated tendering, the samples of cloth which had been treated with tit fluoride and soap retained 84:% of their strength on the average, whereas the samples which had been finished without fluorides and soap retained. only 28% oftheir original strength.

Example H iffotton cloth was dyed with 10% of suliogene carbon in a jig. The dyed cloth when dry was dippedinto a solution containing 2 /2 parts of sodium fluoride and Z parts of granulated tit soap in parts of water. The cloth was then wrung out in a wringer so that it retained about its own weight of solution. The treated cloth was dried and then tendered by heating for 72 hours in an oven at 125 C. The treated cloth retained 97% of its original strength, whereas the control, a sample of the same dyed cloth which had not been aftertreated, retained only 34% of its original strength.

As shown above in the examples given, the cloth which had been treated with soap and soluble fluorides tendered less rapidly than cloth which had not been aftertreated. Moreover the dry cloth was soft and had no tendency towards dusting, Furthermore, the treatment of the till cloth with fluoride in the presence of the soap did not interfere with the stiffening effect of the finish employed.

Although the invention is not limited to the treatment of the textile materials with any specific proportions of soap and fluoride, our experience has shown that it is preferable to employ such proportions of soap and fluoride as to produce materials having thereon at least one-fifth as much total fluoride and soap by weight as dye. Especially desirable results are obtained when the total amount of fluoride and soap is about onehalf of the weight of dye on the material treated. Thus, when fibers or fabrics are dyed with about 10% (based on the weight of the fibre or fabric) of a sulfur dye such as sulfogene carbon HXX, sulfogene carbon M (prepared by thionating a mixture of diand tri-nitrophenols) and the like, it is preferable to treat the dyed materials with a soluble fluoride in the presence of a soap in such a manner that a total of about 5% by weight (based on the weight of the dyed materials) of fluoride and soap remains thereon. This may be accomplished, for example, by soaking the dyed materials in a solution having a total soap and fluoride content of about 5% by weight (based on the dyed materials) until the materials take up their own weight of solution, and then drying. It will be apparent that in incorporating a desired amount of fluoride and soap into a material as above described, the absorptive power of the material for the solution should be taken into consideraticn. Obviously, fibers and fabrics are not likely to have the same absorptive capacity for finishing mixtures containing a soap and a fluoride as for water solutions of the soap and fluoride. Moreover, the absorptive capacity of a fabric may vary greatly depending upon whether it is loosely or tightly woven. In general, however, by regulating the concentration of fluoride and-soap in the solution and the amount of solution absorbed by the material treated, practically any desired amount of fluoride and soap may be incorporated into the material.

The ratio of soap to fluoride employed in the treatment of the material cannot be set within very narrow limits because a slight change in the proportion of soap does not cause any sharp change in the properties of the resulting aftertreated dyeing. However, if the ratio of soap to fluoride is less than about 1:19 (by weight) the beneficial effects of the soap are not so evident. On the other hand, the ratio of soap to fluoride should preferably not be greater than about 1:1 because in general the most beneficial effects are obtained with smaller amounts of soap.

Although, in carrying out the invention, any soluble salt of hydrofluoric acid may be employed, the salts of the alkali metals, particularly sodium and potassium salts, and like salts such as ammonium salts, are especially valuable.

The soap employed in accordance with the invention may be any grade, kind, or quality of soap, depending upon the conditions of use, except that it should preferably be a soap which is soluble in water. Moreover, for the avoidance of spots on the materials, the soap employed should preferably dissolve clear in water. It will be understood that the term soap is intended to include not only solid soaps but liquid soaps. We prefer to employ the soaps obtained by saponiflcation of the glycerides of higher fatty acids with bases, or by the reaction of the higher fatty acids with a base directly. In particular we prefer to employ as soaps the alkali metal and alkylolamine oaaeoe salts of the higher fatty acids, such as, for example, the sodium and potassium salts of oleic, ricinoleic and stearic acid and the amine soaps described in U. S. applications Serial Nos. 437,- 937, 437,938 and U. S. Patent No. 1,799,824. Of the alkylolamines soaps, the products obtained by combining fatty acids, such as, for example, oleic, stearic, ricinoleic, and sulforicinoleic acids with diand/or tri-ethanolamines are especially desirable.

In practicing the invention, it is desirable that the soap, among other things, should function as a wetting and penetrating agent. Since soap is a wetting and penetrating agent only in alkaline solution it is advantageous to ensure that the solution of soap and soluble fluoride is definitely alkaline by adding thereto a small amount of an alkaline substance. The particular alkaline substance employed for this purpose is immaterial so long as it does not catalyze tendering or spoil the finish on the cloth. Tri-sodium phosphate or sodium carbonate are particularly suitable because they can be added in dry form. Generally speaking, in the use of the alkaline substance with the soap and soluble fluoride, there is no advantage in employing more than 10 parts of alkaline substance to 90 parts of soap and fluoride on a dry basis.

The soap may be replaced wholly or in part by suitable oils. Suitable oils for this purpose are oils which will wet or penetrate the material and yet have no harmful effect thereon. Such oils are, for example, sulfonated oils which have been fully neutralized, for instance, sulfonated castor oil.

The fluoride and soap may be prepared in the form of a dry mixture, preferably containing a small amount of an alkaline substance, or they may be prepared in solution form. Dry mixtures are advantageous in that they may be stored and shipped economically and need only to be dissolved in a suitable solvent for direct application to the dyed material.

While the invention is not limited by any particular theory, it should be noted that tendering is apparently inherent in the sulfur dye rather than in the. material treated, although, of course, some materials may be more resistant to the tendering action than others. Furthermore, some sulfur dyes are capable of tendering a given material to a much greater extent than other sulfur dyes. Thus, we may apply our invention to the treatment of materials dyed with sulfogene navy blue R L (prepared by the thionation of an indophenol derived from nitroso phenol and o-toluidine) sulfogene green M (prepared by the thionation of an indophenol derived from p-amidophenol and Cleves acid), and sulfogene Bordeaux B (prepared by the thionation of the azine derived from p-amido-phenol and m-toluylene diamine. We have found, however, that sulfur black dyed materials exhibit tendering to a much greater degree than other extensively used sulfur dyed materials and it is in the treatment of materials dyed with sulfur black dyes (e. g., those prepared by the thionation of nitro-phenolic bodies) that our invention yields especially advantageous results.

It will be understood that the stabilizing agents herein described may, in accordance with the invention, be applied to any material which is dyed with a sulfur dye. Very desirable results are obtained where the material dyed and treated with the anti-tendering agent contains plant fibre or synthetic fibre of cellulosic origin, such as, for

1 y example, cotton, linen, ramie, jute, rayon. cellulose acetate and the like.

The efliciency of the tendering inhibitors here-- in described is such that sulfur black dyed materials or other sulfur dyed materials treated therewith remain substantially unaltered after longperiods of storage, even in warm, damp places. The combination of soap and fluoride is particularly desirable because of the homogeneous and thorough penetration and distribution of the tendering inhibitor in the materials treated and the fact that the dyed materials are'soft and non-dusting.

As many apparent and widely different embodiments of this invention may be made without departing from the spirit thereof, it is to be understood that 'we do not limit ourselves to the foregoing examples or description except as indicated in the following claims.

We claim:

. 1. Materials dyed with a sulfur dye and having thereon a soluble fluoride and a soap.

2. Materials dyed with a sulfur dye and having thereon a water-soluble salt of hydrofluoric acid and a water-soluble soap.

3. Sulfur black dyed materials'having thereon a soluble salt of hydrofluoric-acid and a soap.

4. Sulfur black dyed materials having thereon an alkali metal salt of hydrofluoric acid and a water-soluble soap.

5. Sulfur black dyed materials having thereon at least about one-fifth as much total soap and soluble fluoride as dye. I

6. Sulfur black dyed materials havlng'thereon about one-half as much total soap and soluble fluoride as dye.

7. Sulfur black dyed materials having thereon a soap and a soluble fluoride, the ratio of soap to fluoride being to 1:1. I

8. Sulfur black dyed materials having thereon a soap and sodium flouride.

9. Sulfur black dyed cotton materials having thereon a water soluble soap and a water-soluble fluoride, the ratio of soap plus fluoride to'dye bewithin the range of about 1:19

ing about 1:2 and the ratio of soap to fluoride being within the range of about 1:19 to 1:1.

10. Sulfur black cured cotton materials having thereon a water-soluble soap and a water soluble salt of hydrofluoricacid.

11. The process of preventing or retarding tendering in materials dyed with sulfur dyes which comprises treating the materials with a solution of a salt of hydrofluoric acid in the presence of a I water-soluble soap.

12. The process of preventing or retarding tendering in materials dyed with a sulfur black dye which comprises treating the materials with a solution of a salt of hydrofluoric acid in the presence of a soap. 13. The process of preventing or retarding tendering in materials dyed with a sulfur black dye which comprises treating the materials with an alkaline solution containing a salt of hydrofluoric acid and a soap. k

-14. The process of preventing or retarding tendering in materials dyed with a dye prepared by thionating a nitro-p'henol derivative which comprises homogeneously incorporating with the dyed inaterials a soap and a soluble fluoride.

15. The process of preventing or retarding tendering in materials dyed with a sulfur dye which comprises treating the materials with a finishing mixture containing a soluble fluoride and a soap;

16. The process of claim 11 in which at least a part of the soap is replaced by a neutral sulfonated oil.

17. The process which comprises treating sulfur dyed materials with a fluoride and a soap selected from the group consisting of alkali metal and alkylolamine salts of higher fatty acids.

" 18. Materials dyed with a sulfur dye and having thereon a water soluble salt of hydrofluoric acid and a water soluble soap selected from the group consisting of alkali metal salts of higher fatty 

